1## Copyright (C) 2000 Kai Habel
2##
3## This program is free software; you can redistribute it and/or modify it under
4## the terms of the GNU General Public License as published by the Free Software
5## Foundation; either version 3 of the License, or (at your option) any later
6## version.
7##
8## This program is distributed in the hope that it will be useful, but WITHOUT
9## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
11## details.
12##
13## You should have received a copy of the GNU General Public License along with
14## this program; if not, see <http://www.gnu.org/licenses/>.
15
16## -*- texinfo -*-
17## @deftypefn {Function File} { } fnplt (@var{pp}, '@var{plt}')
18## plots spline
19##
20## @seealso{ppval, spline, csape}
21## @end deftypefn
22
23## Author:  Kai Habel <kai.habel@gmx.de>
24## Date: 3. dec 2000
25## 2001-02-19 Paul Kienzle
26##   * use pp.x rather than just x in linspace; add plt parameter
27##   * return points instead of plotting them if desired
28##   * also plot control points
29##   * added demo
30
31function [x, y] = fnplt (pp, plt)
32
33  if (nargin < 1 || nargin > 2)
34    print_usage;
35  endif
36  if (nargin < 2)
37    plt = "r;;";
38  endif
39  xi = linspace(min(pp.breaks),max(pp.breaks),256)';
40  pts = ppval(pp,xi);
41  if nargout == 2
42    x = xi;
43    y = pts;
44  elseif nargout == 1
45    x = [xi, pts];
46  else
47    plot(xi,pts,plt,pp.breaks,ppval(pp,pp.breaks),"bx;;");
48  endif
49
50endfunction
51
52%!demo
53%! x = [ 0; sort(rand(25,1)); 1 ];
54%! pp = csape (x, sin (2*pi*3*x), 'periodic');
55%! axis([0,1,-2,2]);
56%! title('Periodic spline reconstruction of randomly sampled sine');
57%! fnplt (pp,'r;reconstruction;');
58%! t=linspace(0,1,100); y=sin(2*pi*3*t);
59%! hold on; plot(t,y,'g;ideal;'); hold off;
60%! axis; title("");
61